Bale wrapping device

ABSTRACT

The invention concerns a bale wrapping device comprising a wrapping platform ( 1 ) on which a bale ( 11 ) is rotatable about a horizontal axis ( 9 ) and a support frame ( 23 ), which carries at least one rotating arm ( 17 ) rotatable about a vertical axis ( 19 ) by means of a rotation drive ( 18, 21 ). In order to reduce the overall height of the rotating arm drive, it is proposed according to the invention that the rotation drive ( 18, 21 ) is arranged between the upper side (A) of the support frame ( 23 ) and the under side (B) of the rotating arm ( 17 ).

[0001] The invention concerns a bale wrapping device according to the precharacterising clause of claim 1.

[0002] Both round and rectangular bales are wrapped. There are currently two basic bale wrapping systems in practical use. In the wrapping platform system, during rotation of the bale about a horizontal axis and simultaneous rotation about a vertical axis, sequential overlapping layers of film are laid two or three times round the entire outer surface of the bale. In the case of the rotating arm device, the bale does still lie on a type of wrapping platform which rotates the bale about its horizontal mid-axis, but the wrapping platform does not simultaneously rotate about its vertical axis. Rather, the relative rotation between bale and supply roll is generated with a rotating arm circling round the bale and carrying the film roll at its outer end.

[0003] All the bale wrapping devices of the aforementioned type currently available on the market now use hydraulic torque motors, such as orbital motors with a gearbox attached whose output shaft is linked non-rotatably to the rotating arm for rotary drive of the rotating arm. In addition, arranged between the hydraulic motor and the gearbox is a multiple disk brake, which stops the rotating arm immediately if an appropriate signal is issued by a safety apparatus (leading shut-off handle). The braking distance of the rotating arm must not be longer after the shutting-off than the actuation path of the shut-off handle, in order to avoid accidents and injuries.

[0004] In the case of a bale wrapping device in a brochure from the firm of Maschinenfabrik Bernard Krone GmbH entitled “Combi Pack” with the printed identification Nie 985/3/99, the gearbox is designed as a spur gear system and attached at the height of the support frame for the rotating arm on the support frame. See also DE 197 55 605 C1. Above this are arranged a multiple disk brake and a hydraulic motor.

[0005] A further embodiment is disclosed in a brochure from the firm of Claas Vertriebsgesellschaft for the “Rundballenpressen-Wickler-Kombination Rollant 250 RC Uniwrap” with the printed identification 08/00 (Gie) German 200/1114. In this case, a hub for mounting the rotating arm is attached to a frame assembly and above the frame assembly is arranged a right angle drive with horizontal hydraulic motor.

[0006] In addition there are rotating arm drives having a chain drive in place of a gearbox.

[0007] All the known embodiments of rotary drives for the rotating wrapping apparatus have the great disadvantage of a large overall height.

[0008] Since the hydraulic motor, multiple disk brake and gearbox as well as the rotating arm mounting are arranged one above the other, these structural members extend upwards relative to the support frame and form the highest point. Thus these constructions restrict the overall height of the device, which is critical particularly for wrapping devices for bale diameters about or above 1.65 m. Apart from this, the drives may easily become damaged when passing through entranceways.

[0009] The object of the invention is to improve the rotating arm drive of bale wrapping devices.

[0010] To achieve the stated object, the bale wrapping device of the aforementioned type is distinguished in that the rotating drive is arranged between the upper side of the support frame and the under side of the rotating arm. For further details of how the invention is configured, reference is made to the subclaims.

[0011] In this manner, it is achieved that no components of the drive project upwards or downwards. The previous overall drive height is approximately halved.

[0012] A simple design consists therein that a torque motor is arranged in the support frame and its drive shaft is connected directly or indirectly and non-rotatably to the rotating arm.

[0013] In a preferred form of the invention, the rotating motor is connected to a gearbox, particularly a planetary gearbox arranged in the rotating arm. In addition, there are the following advantages:

[0014] despite the torque motor and gearbox, the drive forms a compact modular unit

[0015] the compactness of a planetary gearbox permits greater reductions and therefore hydraulic motors of smaller absorption capacity

[0016] due to the greater gearing ratio, the self-locking of the gearbox when static is relatively larger, so that the load holding valves previously usually necessary are dispensed with

[0017] modular design

[0018] logistics-friendly

[0019] multiple disk brake can also be integrated

[0020] maintenance-free, since leakage oil lubrication used

[0021] lower weight

[0022] simple cladding possible, since design symmetrical above and below

[0023] The invention will now be explained in more detail below with reference to exemplary embodiments. In the drawings:

[0024]FIG. 1 is a side view of a bale wrapping device of known design,

[0025]FIG. 2 is a side view according to FIG. 1 of a bale wrapping device with a drive according to the invention for the rotating arm of the wrapping apparatus,

[0026]FIG. 3 is a schematic representation of a first example of a rotating arm drive,

[0027]FIG. 4 is a schematic representation of a second example of a rotating arm drive,

[0028]FIG. 5 is an enlarged representation, a view of the rotating arm drive according to FIGS. 2 and 3, with rotating arm and support frame partially omitted,

[0029]FIG. 6 is a view along the direction of the arrow X in FIG. 5,

[0030]FIG. 7 is a side view in enlarged representation of an alternative rotating arm drive with rotating arm and support frame partially omitted, and

[0031]FIG. 8 is a view according to FIG. 7 of another example of a rotating arm drive.

[0032]FIG. 1 shows a bale wrapping device of known design for covering a harvested crop bale with film. The bale wrapping device substantially comprises a fixed wrapping platform 1 with drivable conveying elements 2 and a wrapping apparatus 3 with a rotating arm 4, which is mounted in a support frame 6 rotatable about a vertical rotation axis 5 and carries a film roll 7 at its lower end, as well as a stretch unit (not shown).

[0033] During the wrapping process the film roll 7 is moved round in a rotation movement in a rotation direction 8 about the vertical axis 5 around the harvested crop bale 11 which turns about a horizontal rotation axis 9 in a rotation direction 10, whereby the film is pulled off the film roll 7 and wrapped round the harvested crop bale 11. The drive of the bale 11 and the drive of the rotating arm 4 work in a particular gearing ratio to one another such that the film layers wound around the bale 11 overlap through the simultaneous rotation of rotating arm 4 and bale 11.

[0034] The known drive system for the rotating arm 4 shown in FIG. 1 comprises a hydraulic motor 12, for instance a planetary roller motor, a multiple disk brake 13, a rotating arm mounting 14 in the support frame 6 and a chain drive 15 between the rotating arm mounting axis 5 and the output shaft of the multiple disk brake 13. The chain drive 15, multiple disk brake 13 and hydraulic motor 12 are arranged one above the other and eccentrically relative to the rotation axis 5 of the rotating arm 4. The hydraulic motor 12 extends upwards far beyond the support frame 6.

[0035]FIG. 2 shows an embodiment of the novel drive 16 of the rotating arm 17 with a planetary gearbox 18 arranged coaxially with the rotation axis 19 of the rotating arm 17 and spatially between the rotating arm upper and under sides and attached by means of an add-on console 20 as rotating arm assembly group on the rotating arm 17. A hydraulic motor 21 is placed on the planetary gearbox 18 and attached by means of an add-on console 22 as frame assembly to the support frame 23. The overall modular unit, comprising a hydraulic motor 21 and a planetary gearbox 18 is thus arranged between the support frame upper side A and the rotating arm under side B. The gear reduction ratio of the planetary gearbox 18 in the example shown is i=6:1, although it may be higher or lower.

[0036]FIG. 3 shows an example of the drive 16 according to the invention for the rotating arm 17, which drive is not shown in any more detail in FIG. 2. The drive comprises a one-stage planetary gearbox 18 with a sun gear 24, at least one planetary gear 26 mounted in a web 25 and one internally geared wheel 27. The drive shaft 28 of the hydraulic motor 21 arranged in fixed position on the support frame 23 and coaxially to the rotation axis 19 of the rotating arm 17 is linked non rotatably to the sun gear 24, which engages with several, for instance three, planetary gears 26. The planetary gears 26 are rotatably mounted in the web 25 or planet support. The web 25 or planet support is firmly attached to the hydraulic motor 21, i.e. also linked to the support frame 23, and forms the stationary component of the planetary gearing 18. Apart from the sun gear 24, the planet gears 26 are also in engagement with the rotatably mounted internally geared wheel 27, to which the rotating arm 17 is attached. Arranged between the fixed position web 25 and the drive shaft 28 of the sun gear 24 is a known multiple disk brake 29, whose braking effect is brought about through spring force, while its opening is brought about through the externally supplied oil pressure. It serves, for instance, to hold the rotating arm 17 in a particular basic position when not in operation. Since the multiple disk brake 29 is arranged coaxially with the rotation axis 19 of the sun gear 24 in the planetary gearing 18, the overall height remains low despite the integrated multiple disk brake 29. Mounting of the rotating arm 17 is effected by roller bearings 30 arranged coaxially relative to the drive shaft 28 between rotating internally geared wheel 27 and stationary web 25.

[0037]FIG. 4 differs from the example shown in FIG. 3 in that the internally geared wheel 31 forms the stationary member firmly linked to the hydraulic motor 32 and the support frame 33, while output proceeds via the rotatably mounted web 35 firmly attached to the rotating arm 34. Inaddition, no multiple disk brake is provided.

[0038] Installation of the drive 16 according to FIGS. 2 and 3 is most clearly visible from FIGS. 5 and 6. The hydraulic motor 21 is placed directly on the housing 36 of the planetary gearbox 18 and forms a modular unit therewith, which is rigidly attached to the support frame 23. The gearbox housing 36 of the planetary gearbox 18 according to FIG. 3 has a ring flange 37 which is firmly screwed to the built-on console 22. The built-on console 22 is welded to the support tube end 38 of the support frame 23. The rotating arm 17 is also made of tube and carries a built-on console 20 in mirror-image arrangement. The built-on console 20 is firmly screwed to a ring flange 39 of the internally geared wheel 27. During assembly, the modular unit is initially screwed to the frame 23. Then the rotating arm 17 is screwed to the internally geared wheel 27, so that the rotating arm 17 is rotatable about the vertical rotation axis 19 with the internally geared wheel 27. Installation of the drive of the rotating arm 34 according to FIG. 4 takes place in similar manner, although the lower built-on console is attached to the rotating arm 34 not as a mirror-image of the upper built-on console, but identically to the upper built-on console.

[0039] In the example according to FIG. 7, the drive of the rotating arm 40 comprises a hydraulic motor 42 arranged in the support frame 41 with a flange-mounted angular gear 43, whose drive shaft 44 is attached non-rotatably to the rotating arm 40.

[0040] The example of an alternative rotating arm drive shown in FIG. 8 includes a hydraulic torque motor 45 or an electric motor, which is arranged upright in the support frame 46 with drive shaft 49 arranged coaxially with the drive axis 47. 

1. Bale wrapping device comprising a wrapping platform (1) on which a bale (11) is rotatable about a horizontal axis (9) and a support frame (6) having at least one rotating arm (4) rotatable by means of a rotation drive (12) about a vertical axis (5), characterised in that the rotation drive (18, 21, 29, 32, 42, 43, 45) is arranged between the upper side (A) of the support frame (23, 33, 41, 46) and the under side (B) of the rotating arm (17, 40, 48).
 2. Bale wrapping device according to claim 1, characterised in that a torque motor (45) is arranged in the support frame (46) and its drive shaft (49) is directly or indirectly and non rotatably linked to the rotating arm (48).
 3. Bale wrapping device according to claim 2, characterised in that a torque motor (42) is arranged horizontally in the support frame (41) and is linked to the rotating arm (40) via a gearbox, particularly an angular gearbox (43).
 4. Bale wrapping device according to claim 2, characterised in that the torque motor (21) has a gearbox arranged in the rotating arm (17) downstream of the torque motor (21).
 5. Bale wrapping device according to claim 4, characterised in that the gearbox is a single or multiple-stage planetary gearbox (18, 31, 35), comprising a sun gear (24) on the input side, directly or indirectly and non rotatably linked to the drive shaft of the torque motor (21, 32), one or more planetary gears (26) mounted in a web (25, 35), and a ring gear (27, 31).
 6. Bale wrapping device according to claim 5, characterised in that the web (25) comprises the fixed member firmly attached to the support frame (23), while the ring gear (27) is attached to the rotating arm (17) and serves as a drive.
 7. Bale wrapping device according to claim 5, characterised in that the ring gear (31) comprises the fixed member firmly attached to the support frame (33) and the drive takes place via the web (35) attached to the rotating arm (34).
 8. Bale wrapping device according to one of the claims 1, 2 and 4 to 7, characterised in that the drive shaft (49) of the torque motor (45) and/or the rotation axis (19) of the sun gear (24) is arranged coaxially relative to the rotation axis (19, 47) of the rotating arm (17, 48).
 9. Bale wrapping device according to one or more of the preceding claims, characterised in that one or more brake members (29) are assigned to the torque motor (45) and/or the gearbox (18, 43) in order to stop and/or hold the rotating arm (17, 48) in predetermined positions.
 10. Bale wrapping device according to one or more of the preceding claims, characterised in that the torque motor (21, 32, 42) and the gearbox (18, 31, 43) are designed as a modular unit.
 11. Bale wrapping device according to one or more of the preceding claims, characterised in that the torque motor (45) is a hydraulic or electric motor. 